Transmission mechanism



A. A. WIEDMAlr-:R

TRANSMISSION MECHANISM med May rr, 1928 .lllulllllllllntllllllllllll'll u July 9, V1929.

Patented July 9, 1929.

UNITED STATES .ARTHUR A. WIEDMAIER, OF CLEVELAND, OHIO, `ASSGNOR OF ONE-HALF TO LLOYD 1,719,861 :PATENT OFFICE.

ivi. FIELD, `or onnvntniiin,` oI-rro.

TRANSMISSION MECHANISM.

Application `ined May 7, 1928. serial No. 275,580.

rlhe present application pertains especially to a variable speed transmission mechanism associated with the rear axle assembly ot a motor driven vehicle, preferably in that portion otthe Vrear axle housing `which contains i the dillerential mechanism. The invention, however, is also applicable to industrial machinery equipped with change speed mecha# iiisin, such as Well drilling machinery, ditch diggers, rolling mills and the like.

The principal object of the invention is to provide a device to be used in conjunction with the usual variable speed transmission mechanism and adapted to add at least one speed to every speed obtainable by said mechaiiisni. This result accomplished by the use ot a coniparatively small number of parts made possible by the use ol a pair of concentric gears ot unequal diameter constituting one of the principal characteristics ol the in vention. i

These unequal gears are rotatably mounted near the confronting ends ot theV axle shafts and outwardly o'l' the differential gearing. rllhe intermediate pinions ot the differential gearing are carried by arms of a spider Which loats bet-Ween the axle shafts. Intermediate transmission gears connecting the unequal gears are journalled around or on the spider arms. One ot' the unequal gears is constantly driven by the propeller sh aft. A clutch; member is provided `for selectively conneetingthe remaining unequalgeifir tothe gear driven by the propeller shaft or to a stationary membei'. The latter connection effects a change of speed between the driven gear and the axle sliaitts, While the former connection constitutes a direct drive whereby both unequal gears and the di llerential `mechanism are rotated bodily With the axle shafts.

The inventionis fully disclosed by Wayiol example in the following description and in the accompanying drawing in which the tigure is a longitudinal horizontal section ot a variable speed transmission mechanism constructed according to the invention.

The numeral l indicates the central portion oit the rear axle housing usually em` ployed for accommodating the differential '.inechanism. A pair of aligned axle shafts 2 and 3 extend to the center of the housing in the usual manner, and are suitably ournalled in external members which need not be illus trated in the present instance,

lileirental gears el are secured en the conm 2. lnto this ring V['ittcd abearing race l0 retained by a collar ll threaded into the ring. The dill'erential gear l adjacent this structure has a sleeve 4l on which is mounted a ball bearing l2. A dillerential casing 13 has an integral collar 1.3 loosely surrounding the shatt 2 and carrying Va ball race la which cooperates with the race l0 in carrying ball `bearings `l5. To the side ot the casing i3 is secured, as by Welding,` a. bevel ring gear 13. At the .tree edge of the casin g l3 is atlange 2l to which is secured a driven gear 22 by .means oit a bolt 23.

The usual propeller shaitt 24 Which extends into the casing` carries abevel pinion 25 `meshing `With the gear 22. The speed oi the propeller sha-tt is controlled by the erdinziry transmission mechanism, and 'the drive lietn'een the propeller shalt and the axle sha tts is lurther niodihed by the transmission mech anism constituting the present invention.

i The ditlei'ential casing is completed by an enclosure plate secured to the `flanged end of the member 13` by means oit bolts "27 and luiving its centraliportion 'formed with a circular series of clutch teeth 23 surrounding the axle 3 at some distancetherefrom. The dit l'erential gear l at this side has a sleeve el around which is mounted a ball bearing 29 for the support` oil' a transmission gear 30 oil smaller diameter than the other transmis` sion gearlG. To the ends oil" the spider arm G are lixedly secured bearing members 31 on which are journalled intermediate gears 32 meshing with the unequal gears 'lG and 30, so that the axis ol the intermediate gears are non-perpendicular to the axle sliaitts 2 and 3. Ball bea-rings 33 are interposed between each ol? the sloped gears 32 and the bearing); member 3l on which it is mounted. A ball bearing 34 litted in the plate 2G permits the smaller gear 30 to turn relatively to the dit :terential casing.

The gear 30 has an extended sleeve 35 loosely surrounding the shaft and on which. splined a clutch .member 36. On the and, al?

llll

this member are clutch teeth 37 adapted to engage with the clutch teeth 28 whereby to lock the gear 30 to the transmission easing and gear16. A fixed or stationary member 38 extends inwardly ot' the housing l and is formed with a ring 39 concentric with the axle 3 and surrounding the same. Into this ring is iitted a race 1 0 which, in conjunction with the closure plate 26, supports a set et' ball bearings t1 which permit rotation ot the diii'erential casing around the axle shafts. The member 4t() is retained by a ring 4-2 threaded into the ring'39 and loosely sun rounding'the clutch member 36. The ring #l2 has a series of clutch teeth Li3 engageable by a peripheral series ot' teeth lli on the clutch member 36, whereby the sleeve o't the gear 30 may be locked to the stationary member 39.

A shifting yoke l5 mounted on a rotatable spindle i6 engages in a groove l? in the clutch member inthe usual manner to permit rot. tion of the latter. By means of suitable linkage, the'spindle 46 may be oseillated to slide the clutch member 36 on the sleeve 35.

In the operation of the device the gear 22 -is constantly driven by the propeller shaft 24, the speed oi which is determined by the usual transmission mechanism. `When it is desired to impart the angular velocit el the, gear 22 to the axle shafts, the clutch member 36 is engaged with the teeth 28 oi the easing plate 26. The transmission or unequal gears 16 and 30 are thus turned bodily vwith the differential easing, whereby the spider 5 is also turned bodily and no change in speed occurs through the intermediate VVgears 32. In order to modify the speed of the axle shafts, the clutch member is shifted so that its teeth i4 engage the teeth 43 ot the stationary member 42, whereby the smaller gear 30 is held against rotation. The larger transmission gear 16 turns with the ditterential easing 19 and thereby turns the intermediate gears 32 around the bearing men'ibers 3l. The intermediate gears on thus turning against the .fixed member 30, cause the ditferential gearing and spider to turn around the axis of the shafts 2 and 3 ata smaller .angular Velocity than the driven gear 22,

the ratio of decrease being the rat-io of the diameters of the gears 30 and 16.

VA neutral adjustment of the clutch member between the teeth 2S and i3 is not, eontemplated, the actual neutral position being the direct drive accomplished by connecting the clutch to the teeth 28 oli the easing plate 26.

Although a specilic embodiment olf the invention has been illustrated and described, it will be understood that various alterations in the details of' construction may be made without departing trom the seope ol the invention as indicated by the appended claims.

lllhat I claim is l. In a variable speed transmission, a pair ot axle sha tts, dili'erential gears secured on the confronting ends ot said shatts, a spider disposed between said ends, dillin-ential pinions on the arms ot said spider and meshing with said dilli'erential gears, transmission gears ot unequal dian eter rotatably mounted at said shatt ends, bearing members earried by the arms of said spider, intermediate gears journalled on said bearing membersI and connecting said transmisison gears, means for driving one ot said transmission gears, and means for fixing the remaining unequal gear against rotation.

2. In a variable speed transmission, a pair ot axle shafts, ditl'erential gears secured on the confronting ends ot said shafts, a spider disposed between said ends, and ditllerential pinions mounted on and supported solely by the arms ot said spider and meshing with said ditierential gears.

3. In a variable speed transmission, a pair of axle shafts, differential gears secured on the confronting ends ot said shatts, a spider disposed between said ends, differentialY pinions on the arms of said spider and meshing with said dilllerential gears, transmission gears ot unequal diameter rotatably mounted at said shaft ends, bearing members carried by the arms ot said spider, intermediate gea rs yournalled on said bearing membersl and connecting said transmission gears, means l'or driving one ot said transmission gears, a stationary member, and a clutch member slidably mounted on the remaining unequal gear and adapted forl connection selectivelyto said driving gear or the stationary member.

In testimony whereof I aliix my signature.

ARTHUR A. IVIEDI'A IER. 

